faq/extensions.html - gerrit/www.eclipse.org/birt - Git at Google

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 <p class="head">BIRT FAQ</p>
 <p class="subhead">Extensions</p>

 <h1>Extensions</h1>

 <h2>Q: Can I extend BIRT?</h2>
 <p>
 Yes, BIRT provides several extension points:
 <ul>
 <li>Data access extensions through BIRT's Open Data Access (ODA) framework.
 <li>Extended data access UI using the Eclipse plugin framework.<li>Extended report items that add visual items such as gauges, etc.
 Includes design-time UI support.<li>Scripting within a report. Scripting can access application-specific
 business logic implemented as Java classes.
 <li>Rendering extensions that produce additional report output formats.
 </ul>
 </p>

 <h2>Q: How can I create a custom report item such as a stop light?</h2>
 <p>
 How Java developers could extend the basic BIRT model through the
 creation of Java objects that are accessed through BIRT script.  For
 instance, a company would like to develop a propietary Stop Light Display
 for use in a management summary report, this display would have a
 significant amount of business logic and display logic that they would like
 to implement in Java.
 <br><br>
 ROM calls this an "extended item". The development team is working on a
 specification of exactly how this will happen. Briefly, you start by
 creating an extension definition file, something like that created for
 plug-ins in Eclipse. In that file you identify the element name, the
 properties, and the Java classes to use in the Designer, Report Engine. The
 Designer class paints the design-time view of the element using SWT (or can
 just return an image.)
 <br><br>
 The Report Engine has two phases: the Factory (which creates the report) and
 the Presentation phase which renders the report to HTML, FO, PDF, etc. The
 extension file provides separate classes for each phase. The Factory class
 is often optional; even without it the Factory can figure out (from the
 property definitions) what data needs to be stored in the report document.
 <br><br>
 The Presentation class does the bulk of the work. Let's take the simplest
 case where the element can be represented by an image. Your stop light
 example fits this well. In this case, the Presentation Java class gets two
 pieces of information: the element design (or definition) and the element
 instance. The element design holds all the properties the user set in the
 designer. Perhaps here that includes the color settings, the threshold for
 which light to show, etc.  The element instance provides the data. Suppose
 that the stoplight shows actual sales as a percent of quota. If so, we can
 get this percent from the element instance. We then compare this with the
 design setting for the threshold, and determine say, that the ratio is 90%,
 and so we should show the yellow light.
 <br><br>
 We then create an image and return it to the Report Engine, which "does the
 right thing" to put the image into the HTML file, PDF or whatever.
 <br><br>
 Notice that, in this second case, no JavaScript is needed. Adding an
 extended item is something that a skilled Java developer would do. Once
 installed in BIRT, it would be automatically available to all reports as
 just a BIRT-defined report item.
 <br><br>
 That's the high level answer. Please take a look at the extension
 specification once it is released and see if it provides the details you'd
 need to create such an extension.
 </p>

 <h1>Data Extensions</h1>
 <p>
 See additional discussion of data extensions on the
 <a href="data.html">Data FAQ page</a>.

 </body>
 </html>
	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 transitional//EN">
	<html>

	<head>
	<title>BIRT FAQ</title>
	<link rel="stylesheet" href="../style/compose.css" type="text/css"/>
	<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
	</head>

	<body>

	<p class="head">BIRT FAQ</p>
	<p class="subhead">Extensions</p>

	<h1>Extensions</h1>

	<h2>Q: Can I extend BIRT?</h2>
	<p>
	Yes, BIRT provides several extension points:
	<ul>
	<li>Data access extensions through BIRT's Open Data Access (ODA) framework.
	<li>Extended data access UI using the Eclipse plugin framework.<li>Extended report items that add visual items such as gauges, etc.
	Includes design-time UI support.<li>Scripting within a report. Scripting can access application-specific
	business logic implemented as Java classes.
	<li>Rendering extensions that produce additional report output formats.
	</ul>
	</p>

	<h2>Q: How can I create a custom report item such as a stop light?</h2>
	<p>
	How Java developers could extend the basic BIRT model through the
	creation of Java objects that are accessed through BIRT script. For
	instance, a company would like to develop a propietary Stop Light Display
	for use in a management summary report, this display would have a
	significant amount of business logic and display logic that they would like
	to implement in Java.
	<br><br>
	ROM calls this an "extended item". The development team is working on a
	specification of exactly how this will happen. Briefly, you start by
	creating an extension definition file, something like that created for
	plug-ins in Eclipse. In that file you identify the element name, the
	properties, and the Java classes to use in the Designer, Report Engine. The
	Designer class paints the design-time view of the element using SWT (or can
	just return an image.)
	<br><br>
	The Report Engine has two phases: the Factory (which creates the report) and
	the Presentation phase which renders the report to HTML, FO, PDF, etc. The
	extension file provides separate classes for each phase. The Factory class
	is often optional; even without it the Factory can figure out (from the
	property definitions) what data needs to be stored in the report document.
	<br><br>
	The Presentation class does the bulk of the work. Let's take the simplest
	case where the element can be represented by an image. Your stop light
	example fits this well. In this case, the Presentation Java class gets two
	pieces of information: the element design (or definition) and the element
	instance. The element design holds all the properties the user set in the
	designer. Perhaps here that includes the color settings, the threshold for
	which light to show, etc. The element instance provides the data. Suppose
	that the stoplight shows actual sales as a percent of quota. If so, we can
	get this percent from the element instance. We then compare this with the
	design setting for the threshold, and determine say, that the ratio is 90%,
	and so we should show the yellow light.
	<br><br>
	We then create an image and return it to the Report Engine, which "does the
	right thing" to put the image into the HTML file, PDF or whatever.
	<br><br>
	Notice that, in this second case, no JavaScript is needed. Adding an
	extended item is something that a skilled Java developer would do. Once
	installed in BIRT, it would be automatically available to all reports as
	just a BIRT-defined report item.
	<br><br>
	That's the high level answer. Please take a look at the extension
	specification once it is released and see if it provides the details you'd
	need to create such an extension.
	</p>

	<h1>Data Extensions</h1>
	<p>
	See additional discussion of data extensions on the
	<a href="data.html">Data FAQ page</a>.

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	</html>